Eccentric clamp for manufacturing eccentric sample

Abstract

The utility model relates to the technical field of electric power fittings, and discloses an eccentric clamp for manufacturing an eccentric sample, which comprises a chuck, a spiral elastic coiled wire is processed on the working circular surface of the chuck, a first claw, a second claw and a third claw are sequentially arranged in the elastic coiled wire at equal intervals, and the first claw, the second claw and the third claw are arranged on the working circular surface of the chuck. The head portions of the centered ends of the first claw, the second claw and the third claw are machined to be sword-head-shaped inclined clamping faces. A step is machined on the working face of the centering end of the first claw, and correction blocks of various specifications are arranged on the transverse face of the step in a clamped mode. According to the eccentric clamp for manufacturing the eccentric sample, the machining mode of a three-jaw chuck in an original clamp is changed, the designed eccentric three-jaw structure ensures that the eccentric sample is obtained more efficiently in a tension test, the process machining is simplified, the accuracy of the sample cutting position is improved, and the timeliness and the accuracy of the test are also improved. And finally, the processing efficiency of the sample is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of electric power fittings, in particular to an eccentric fixture for manufacturing an eccentric specimen. Background Art

[0002] The bar specimen is the standard specimen for the anchor bolts of the electric power pipe tower project. For all production batches, specimens need to be taken and tensile tests are required as per the requirements. Due to engineering needs, the eccentric specimen needs to be intercepted as close as possible to the edge of the round steel to obtain the best test data. The intercepted specimen has a length of 420 mm and a diameter of 32 mm.

[0003] The eccentric sampling size and scheme can be found in DL / T 1236 "Anchor Bolts and Nuts for Transmission Tower" and GB / T 2975 "Sampling Location and Specimen Preparation for Mechanical Property Tests of Steel and Steel Products".

[0004] In the prior art, the traditional fixture sampling old process is as follows:

[0005] 1. First, level the two ends of the round steel;

[0006] 2. Use a sawing machine to saw the round steel 4 times to intercept a square long material with a length of 420 mm, a width of 45 mm, and a height of 45 mm;

[0007] 3. Use a four-jaw chuck on a lathe to correct and turn one end of the round steel into a circle;

[0008] 4. Use a four-jaw chuck on a lathe to correct and drill a center hole at the other end;

[0009] 5. Use a three-jaw chuck on a lathe to clamp and support one end and rough-turn the outer circle;

[0010] 6. Use a numerically controlled lathe to clamp and support one end and machine the outer circle and cavity.

[0011] This process is cumbersome in processing, inaccurate in specimen interception position, affecting both the timeliness and accuracy of the test. At the same time, the tool consumption (saw blades, lathe tools) for processing is high. This process deviates from the high standards and high timeliness requirements of the electric power industry, and there is an urgent need for an improved eccentric fixture to improve processing efficiency and meet the relevant test needs of the electric power industry. Content of the Utility Model

[0012] (1) Technical Problems to be Solved

[0013] Aiming at the deficiencies of the prior art, the utility model provides an eccentric fixture for manufacturing an eccentric specimen, which changes the processing method of the three-jaw chuck in the original fixture. The designed structure of the eccentric three-jaw ensures more efficient acquisition of the eccentric specimen in the tensile test, and solves the technical problems of cumbersome processing and low processing efficiency in the prior art when using the traditional fixture sampling old process.

[0014] (2) Technical Solutions

[0015] To achieve the above object, the present utility model provides the following technical solution: An eccentric fixture for manufacturing an eccentric specimen, comprising a chuck. A spiral-shaped tightening and loosening wire is machined on the working circular surface of the chuck. Three equally spaced No. 1 claws, No. 2 claws, and No. 3 claws are sequentially installed in the tightening and loosening wire. The heads of the centering ends of the No. 1 claw, No. 2 claw, and No. 3 claw are machined into obliquely clamping surfaces in the shape of sword heads. A step is machined on the working surface of the centering end of the No. 1 claw, and various specifications of calibration blocks are clamped on the transverse surface of the step.

[0016] Further, the front surface of the calibration block is concave-shaped, and the thickness t is 2 - 5 mm.

[0017] Further, a notch of 15×20 mm is cut on the working surface of the centering end of the No. 1 claw to form the above-mentioned step.

[0018] Further, the heads of the centering ends of the No. 1 claw, No. 2 claw, and No. 3 claw are symmetrically cut to form the obliquely clamping surfaces with a depth of 15 mm and an oblique angle of plus or minus 45°.

[0019] Further, the tightening and loosening wire rotates clockwise to control the clamping and loosening of the No. 1 claw, No. 2 claw, and No. 3 claw.

[0020] (III) Beneficial effects

[0021] Compared with the prior art, the present utility model provides an eccentric fixture for manufacturing an eccentric specimen, having the following beneficial effects:

[0022] This eccentric fixture for manufacturing an eccentric specimen changes the processing method of the three-jaw chuck in the original fixture. The designed structure of the eccentric three-jaw ensures more efficient acquisition of the eccentric specimen in the tensile test, simplifies the process processing, improves the accuracy of the specimen intercepting position, and also improves the timeliness and accuracy of the test. Ultimately, the processing efficiency of the specimen is improved. Description of the drawings

[0023] Figure 1 It is the front view of the present utility model and the sectional views of A - A and B - B;

[0024] Figure 2 It is the front view and top view of the calibration block in the present utility model;

[0025] In the figure: 1. No. 1 claw; 2. Calibration block; 3. No. 2 claw; 4. No. 3 claw; 5. Obliquely clamping surface; 6. Tightening and loosening wire; 7. Chuck; 8. Step. Specific implementation manner

[0026] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0027] Please refer to Figure 1-2 , an eccentric fixture for making eccentric specimens, including a chuck 7. A spiral-shaped tightening and loosening wire 6 is machined on the working circular surface of the chuck 7. Three equally spaced first claws 1, second claws 3, and third claws 4 are sequentially installed inside the tightening and loosening wire 6. The opposite ends of the first claws 1, second claws 3, and third claws 4 are machined into inclined clamping surfaces 5 with a sword head shape; a step 8 is machined on the working surface of the opposite end of the first claw 1. Correction blocks 2 of various specifications are clamped on the transverse surface of the step; the front of the correction block 2 is concave-shaped, and the thickness t is 2-5 mm; the tightening and loosening wire 6 rotates clockwise to control the clamping and loosening of the first claws 1, second claws 3, and third claws 4.

[0028] In the above embodiment, a notch of 15×20 mm is cut on the working surface of the opposite end of the first claw 1 to form the step 8.

[0029] In the above embodiment, inclined clamping surfaces 5 with a depth of 15 mm and an oblique opposite direction of plus or minus 45° are symmetrically cut at the opposite ends of the first claws 1, second claws 3, and third claws 4.

[0030] This eccentric fixture for making eccentric specimens has three different methods of installing clamping claws, and the machining position of the specimen is adjusted through three different clamping claw installation methods. The following examples show the assembly methods of three different specifications of specimens.

[0031] Example 1:

[0032] For the M72 specification specimen, through calculation, the required first claws 1, second claws 3, and third claws 4 are made. The specimen is marked by a fitter to find the sampling center and a center hole is drilled. First, the first claw 1 is installed on the chuck 7. After the tightening and loosening wire 6 rotates clockwise idly for two circles, the second claw 3 and the third claw 4 are installed in sequence. The specimen is placed on the inclined clamping surfaces 5 of the second claw 3 and the third claw 4 and pre-clamped. The tailstock center of the machine tool is pushed in. According to the actual size of the outer circle, correction blocks of 2-4 mm are placed for fine adjustment and alignment, and then numerical control programming machining is carried out.

[0033] Example 2:

[0034] For the M64 - sized specimen, calculate and make the required first jaw 1, second jaw 3, and third jaw 4. Use a fitter to mark the specimen to find the sampling center and drill a center hole. First, install the first jaw 1 on the chuck 7. After loosening and tightening the chuck screw 6 and turning it clockwise for one full rotation, successively install the second jaw 3 and the third jaw 4. Place the specimen on the inclined clamping surfaces 5 of the second jaw 3 and the third jaw 4 for pre - clamping. Insert the tailstock center of the machine tool. Depending on the actual size of the outer diameter, place a calibration block of 2 - 4 mm for fine adjustment and alignment, and then perform numerical control programming for machining.

[0035] For the M56 - sized specimen, calculate and make the required first jaw 1, second jaw 3, and third jaw 4. Use a fitter to mark the specimen to find the sampling center and drill a center hole. Rotate the chuck 7 and loosen and tighten the chuck screw 6 to install the first jaw 1 first, and then successively install the second jaw 3 and the third jaw 4 clockwise. Place the specimen on the inclined clamping surfaces 5 of the second jaw 3 and the third jaw 4 for pre - clamping. Insert the tailstock center of the machine tool. Depending on the actual size of the outer diameter, place a calibration block of 3 mm for fine adjustment and alignment, and then perform numerical control programming for machining.

[0036] To sum up:

[0037] The eccentric fixture for making eccentric specimens has changed the processing method of the three - jaw chuck in the original fixture. The designed structure of the eccentric three - jaw ensures more efficient acquisition of eccentric specimens in tensile tests, simplifies the process machining, improves the accuracy of the specimen interception position, and also improves the timeliness and accuracy of the test. Next, compare the old process of the fixture in the existing technology with the new working principle of using this eccentric fixture for making eccentric specimens to verify the above - mentioned technical effects.

[0038] The processing flow of the old sampling process is a single - person and single - machine sequential processing mode. The first step is to use an ordinary lathe to turn both ends of the round steel to flat with a three - jaw chuck, which requires repeated clamping 2 times, taking 0.4 hours, and the tool cost is 0.5 yuan. The second step is to use a sawing machine to saw the round steel into a square, which requires repeated clamping 4 times, taking 2 hours, and the tool cost is 50 yuan. The third step is to use an ordinary lathe to turn one end of the round steel, which has the problem of difficult alignment, with 1 clamping, and this process takes 0.5 hours, and the tool cost is 0.5 yuan. The fourth step is to use an ordinary lathe to drill a center hole at one end, with 1 clamping, taking 0.2 hours. The fifth step is to use an ordinary lathe, with a three - jaw clamping, to initially turn the square blank into a round. This process has a large impact during machining, with 1 clamping, taking 1.5 hours, and the tool cost is 5 yuan. The sixth step is to use a numerical control lathe to finely machine the outer diameter and the cavity. This process has 1 clamping, taking 0.5 hours, and the tool cost is 2 yuan. The old process has a total of 10 clamps, taking 5.1 hours, and the total tool cost is 58 yuan.

[0039] When using the eccentric fixture for making eccentric specimens, the processing flow is a single-operator multi-machine simultaneous processing mode. The first step is to draw lines and drill center holes on a radial drill press, with the characteristics of accurate position, 1 clamping, and a time consumption of 0.2 hours. The second step is to machine the entire outer circle and cavity on a CNC lathe using the newly designed eccentric fixture, with 1 clamping and a time consumption of 1.5 hours, and a tool cost of 4 yuan. The new process has a total of 2 clamps, a time consumption of 1.7 hours, and a total tool cost of 4 yuan.

[0040] It should be noted that in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising a..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0041] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An eccentric fixture for making an eccentric specimen, comprising a chuck (7), characterized in that: A spiral-shaped tension wire (6) is processed on the working circular surface of the chuck (7), and three jaws (1, 2, 3, and 3) are installed in sequence in the tension wire (6) at equal intervals. The centering ends of the jaws (1, 2, 3, and 3) are processed into an inclined clamping surface (5) in the shape of a sword head; a step (8) is processed on the working surface of the centering end of the jaw (1), and correction blocks (2) of various specifications are clamped and arranged on the transverse surface of the step.

2. The eccentric fixture for making eccentric specimens according to claim 1, characterized in that: The front side of the calibration block (2) is in a concave shape, and the thickness t is 2 to 5 mm.

3. The eccentric fixture for making eccentric specimens according to claim 1, characterized in that: A notch of 15×20 mm is cut out on the working surface of one end of the center of the No. 1 claw (1) to form the above-mentioned step (8).

4. The eccentric fixture for making eccentric specimens according to claim 1, characterized in that: The center end heads of the first jaw (1), the second jaw (3) and the third jaw (4) are symmetrically cut with an oblique clamping surface (5) with a depth of 15 mm and an angle of plus or minus 45 degrees.

5. The eccentric fixture for making eccentric specimens according to claim 1, characterized in that: The tension coil (6) rotates clockwise and is used to control the clamping and loosening of the No. 1 jaw (1), the No. 2 jaw (3) and the No. 3 jaw (4).

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